Chuck construction



Nov. 17,- 1936. H H KNOTT 2,061,321

CHUCK CONSTRUCTION Filed Dec. 4, 1934 v v 1 22321456 5;; 650. i c mc/wPatented Nov. 17, 1936 UNITED STATES CHUCK CONSTRUCTION Harry H. Knott,Washingtomlowa, assignor to American Pearl Button 00., Washington, Iowa,

a corporation of Iowa Application December 4, 1934, Serial No. 755,900

4 Claims.

An object of my invention is to provide a chuck for button blanks or thelike, the chuck being comparatively inexpensive to manufacture andsimple in its construction.

More particularly it is my object to provide a chuck constructionespecially adapted for holding button blanks or other semi-fragileelements in such manner that the possibilities of chipping the edges ofthe blank are minimized and also the tendency for the blank to springout of the chuck is minimized;

Still another object is to provide a spindlelike chuck element of thesplit contractible type with a removable element for engaging the buttonblank or. the like in such manner that it is firmly held without dangerof chipping.

Still another object is to provide a split chuck with an annular groovewith which a resilient contractible ring may be associated so that thering itself rather than the metal of the chuck will engage the edge of abutton blank or the like to hold itwhil'e performing operations thereon.

A further object is to provide a removable blank engaging element and amethod for renewing it, which method is simple and quick to perform.

With these and other objects in view my invention consists in theconstruction, arrangement and combination of the various parts of mydevice, whereby the objects contemplated are attained', as hereinaftermore fully set forth, pointed out in my claims and illustrated in theaccompanying drawing, in which:

Figure 1 is a plan View of a chuck construction embodying my invention,showing the button blank received therein.

Figure 2 is a. vertical sectional view on the line 2-2 of Figure 1showing a blank. being held in the chuck and a tool being used on theblank.

Figure 3 is a separated perspective view of my chuck constructioncomprising a spindle-like chuck element and a renewable resilient blankengaging ring.

Figure 4 is a plan view showing the ring in position and partly splitaccording to my method for renewing the ring.

Figures 5 and 6 are enlarged sectional views on the lines 5-5 and 66respectively of Figure 1, illustrating the action of the resilient ringof my chuck.

Figure '7 is a plan view of a conventional chuck; and

Figure 8 is a side elevation of another form of chuck including myinvention, part of the chuck being broken away.

On the accompanying drawing, I have used the reference character A toindicate generally a spindle-like chuck element and B a resilient ringfor association therewith. The chuck A has, as shown in Figure 3, ashank It provided with a cone-portion l2 and an enlarged head it. Thehead M has therein an annular groove l6 terminating in an outersupporting flange Ill. The chuck is split twice at right angles to eachother, they split spaces being indicated at 20. The element A with theexception of the groove l 6 is now in general use and one of such chucksis shown in Figure 7 as A, the parts thereof corresponding to the chuckA, having the same reference numerals with the addition of thedistinguishing characteristic a.

The chuck A is shown as having a button blank 0 therein. These blanksare not always perfectly round and the out-of-roundness of the blank Chas been exaggerated in Figure '7 so that it contacts at but threepoints a with the chuck A. Exaggerated spaces 1) are illustrated whichin actual practice may be only one or two thousandths of an inch, butnevertheless since the flange l8a is non-resilient and the blank itselfis non-resilient, there will be no engagement at these points, so thatthe blank is engaged at but a very small percentage of its periphery.Accordingly, when a tool, such as a grinder, shown at 22 in Figure 2, isused on the blanks many of them are chipped on the edges and some ofthem spring out hi the chuck. Chipped blanks, of course, are unusableand there is therefore considerable waste experienced.

By providing the annular groove Hi to receive the resilient ring B as isobvious from an inspection of Figure 3 I am able to overcome thedifficulties enumerated in connection with the chuck A in Figure 7. Thering is of slightly greater cross sectional thickness than the width ofthe groove, as is evident from Figure 5, so that it must be forced into.the annular groove and will accordingly be retained there by itstendency to re-expand to its original thickness. After it is forced intothe groove a saw or other cutting tool is run through the split spaces20, the vertical one of which has been so sawed through as illustratedin Figure 4 and the horizontal one being now ready for sawing through.

The method of installing the ring just described facilitates theinstallation because it is easier to force the entire ring into thegroove than to force individual segments of the ring into the individualsegments of the chuck and. get the two in proper relative alignment. Thejob can be done in less than half the time by this method.

After the ring segments, which are designated by the reference numeral24, have become too badly worn for further service, they can readily bedug out of the groove segments for the purpose of inserting another ringas just described.

The same out-of-roundness blank C is shown engaged by the chuck A ofFigure l as was illustrated in Figure '7. It will be noted that thesegments 24 conform to the shape of the periphery of the blank, thesectional Figures 5 and 6 showing respectively relatively loose (yetfirm) and tight engagement of the same points on the periphery of lessthan greater radii respectively. Even where the edges of the blank arerelatively loosely engaged as in Figure 5, there would be a slightover-hanging, as indicated at 2B, of the upper edge of the segment 24with respect to the button blank, this deformation of the segmentinsuring against the button blank flipping out of the chuck when a toolis used on the blank. The flange segments l8 back up the segments 24 andserve as supports counteracting the tendency for the blank to enlargethe blank-engaging segments 24.

Heretofore. with all metal chucks the flange segments l8 receivedconsiderable wear and after ,a few months service the chuck A had to bethrown away, as it would no longer hold the blanks. With my removableinsert ring B, however, it is merely necessary to take a few minutestime to renew this element which is very inexpensive and the metalportion of the chuck can thus be used repeatedly for an indefinitelength of time. This obviously effects a considerable economy over theold method.

The chuck A is ordinarily used in a drill press type of button blankmachine. Some of the conveyor types have chucks such as shown in Figure8, except that they are all metal and do not include the annular grooveI6 and the resilient segments 24, which I have already described. Thechuck in Figure 8 is indicated generally by the reference character A"and is of shaft-like construction, similar to the chuck A, but having ataper I2a reversely arranged. On the lower end of the chuck, a thrustball 28 is provided which travels on a cam track (not shown) which atthe proper time raises the chuck, causing the cone lZa to engage areduced portion of the bore in which the chuck is mounted (not shown)for contracting the chuck. The chuck A is contracted by the cone [2asimilarly engaging a part of the machine when the chuck is moveddownwardly.

Chucks such as A of Figure 8, when made of all metal, must have theirupper ends turned down occasionally as they wear away. The chuck mustthen be lengthened so as to retain its original length in the machinefor proper operation. All of this takes considerable time and skill,whereas with my invention the chuck A" can remain in its originaldimensions, the segments 24 being taken out and a new ring B insertedand sawed through, as has been already described, whenever necessary.

From the foregoing description it will be obvious that I have conceiveda novel and economical means for removing the blank engaging element ona button blank chuck or the like and that such element is far superiorto the all metal chuck now in general use. Although I have described thering B as being resilient, it is obvious that the degree of resiliencymay vary greatly, depending upon the material used to form it. I havefound rubber quite satisfactory, although of course, other materialswould be suitable. Also, the rubber may be hard or soft as required anda change of this character, as well as others, may be made withoutdeparting from the real spirit and purpose of my invention, and it is myintention to cover by my claims any modified forms of structure or useof mechanical equivalents, which may be reasonably included within theirscope.

I claim as my invention:

1. In a button blank chuck, a spindle-like chuck element, said elementbeing split into a plurality of parts whereby said parts may be sprungtoward each other, an annular groove in an end of said chuck element, asupporting flange outside of and projecting beyond said groove and aresilient button blank engaging ring partially in said groove andpartially against said flange, said ring being split coincident with thesplit spaces of said chuck element.

2. In a button blank chuck, a spindle-like chuck element, said elementbeing split into a plurality of parts whereby said parts may be sprungtoward each other, an annular groove in an end of said chuck element, asupporting flange beyond said groove and a resilient button blankengaging ring partially in said groove and partially against saidflange.

3. In a chuck construction, a spindle-like chuck element having adepression in one end thereof and an annular groove surrounding saiddepression, an annular flange surrounding said groove and extendingbeyond the bottom of said depression and a resilient blank engaging ringpartially in said groove and partially against said flange, said chuckelement comprising a plurality of parts movable toward each other forcontracting said ring.

4. In a chuck construction, a spindle-like chuck element having adepression in one end thereof and an annular groove surrounding saiddepression, an annular flange surrounding said groove and extendingbeyond the bottom of said depression and a resilient blank engaging ringpartially in said groove and partially against said flange, said chuckelement comprising a plurality of parts movable toward each other forcontract ing said ring, said ring comprising a plurality of parts onefor each part of said chuck element.

HARRY H. KNOTT.

